What type of solder do you use and why?

Riehl Copper solder from Starsound, has given me the best sound. NO LEAD..LEAD free highs. This formula is an original not just a re-label! I have 2 sets of cables both assembled by the same tech. One set with silver based solder the other with Riehl copper based solder. The Riehl based cables gave a much cleaner and more focused presentation along with more articulate mid and upper bass. The prescence of lead makes the others a no brainer!!!

Cardas makes a "quadelectric" solder for audiophile use.

I'm not sure if this will have any bearing, (HA!), seeing from the varieties of solder here, but of the 3, wonder, wbt, cardas, I find cardas to sound the best. how much, I don't know, but it sure seems that way to me. (I don't redo solder to see if there is a difference). I haven't noticed it being any harder to work with, in fact, they are all easy, these 3. I have noticed a noticable improvement washing the surfaces with xlo contact cleaner. I have not found any cold joints with this yet.

Cardas uses a quad-eutectic formulation which has lead, tin, copper, and silver. The point to this is that you would like the solder to contain at least a small amount of whatever metal you are soldering to, so that on a molecular level you get a very good bond. When used with copper wire, silver wire, silver-plated wire, and silver-rhodium plated connectors, I feel it is the best. If you want to save some money, though, plain old 63/37 is an excellent choice (avoid the more common 60/40; it is not eutectic).

Well there is a lot of good solder here. I'll go for Rat Shack lead free stuff. I think it has a 2-3% silver content. It won't kill your brain cells (I'm biased here as I have precious few left to waste) and can be bought around the corner. I have to admit though that my favorite dog is a mutt.

Sincerely,
I remain